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Journal of Consciousness Studies www.imprint-academic.com/jcs Barbara Montero Post-Physicalism For personal use only -- not for reproduction Copyright (c) Imprint Academic 2013 Introduction What is the problem, inherited from Descartes, that we now call ‘the mind–body problem’? In his most recent bo...

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Journal of Consciousness Studies www.imprint-academic.com/jcs

Barbara Montero

Copyright (c) Imprint Academic 2013 For personal use only -- not for reproduction

Post-Physicalism

Introduction What is the problem, inherited from Descartes, that we now call ‘the mind–body problem’? In his most recent book, Jaegwon Kim provides an answer with which many would agree. ‘Through the 70s and 80s and down to this day,’ Kim tells us, ‘the mind–body problem — our mind–body problem — has been that of finding a place for the mind in a world that is fundamentally physical’ (Kim, 1998, p. 2). This problem, which at one time was at home mainly in departments of philosophy, is now studied by a broad range of disciplines. One finds, for example, neuroscientists arguing that certain discoveries about the brain show that consciousness is physical; researchers in artificial intelligence claiming that because human thought can simulated by complex computers, thought requires nothing beyond the physical; and evolutionary biologists declaring that insights into the evolution of the mind indicate that it must be fundamentally physical. But what does it mean to be physical? While the basic results of the research being done may be clear enough, how are we to interpret the further claim ‘and this shows that the mind is physical’? The answer is that we have no idea. I am going to argue that it is time to come to terms with the difficulty of understanding what it means to be physical and start thinking about the mind–body problem from a new perspective. Instead of construing it as the problem of finding a place for mentality in a fundamentally physical world, we should think of it as the problem of finding a place for mentality in a fundamentally nonmental world, a world that is at its most fundamental level entirely nonmental. The mind–body problem, I want to argue, is the problem of determining whether Correspondence: Barbara Montero, Dept. Of Philosophy, University of Pittsburgh, 1001 Cathedral of Learning, Pittsburgh, PA 15260, USA. Email: [email protected]

Journal of Consciousness Studies, 8, No. 2, 2001, pp. 61–80

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mentality can be accounted for in terms of nonmental phenomena. In other words, it is the question, ‘is mentality a fundamental feature of the world?’1

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I: The Current State of the Debate Currently most philosophers working on the mind–body problem see the debate in terms of the physical and the nonphysical: the question most are concerned with is whether mentality is fundamentally physical.2 Indeed, since most think that the mind must be physical, the project they are engaged in is not so much arguing that the mind is physical, but, rather, trying to show how the mind could be physical (given that it is). And so, whether the account of mentality that physicalists propound is expressed in terms of reduction, realization, identity, supervenience, explanation or even elimination, the goal is to provide a plausible theory of mentality (or, as the case may be, a theory that accounts for what we mistakenly took to be mentality) that is compatible with the view that the world is fundamentally physical. For example, if one thinks that it is incumbent on physicalists to explain mentality then the explanation, it is thought, must make reference exclusively to physical phenomena; if one thinks supervenience suffices for physicalism, then the supervenience base must be entirely physical; and so forth. But what does it mean to be physical? It seems that those who take the central concern of the mind–body problem to be the relationship between mental properties and physical properties — and if Kim is right, this is just about everyone — should have at least a rough idea of what it means to be physical, not necessarily a strict definition, but at least a notion of the physical that excludes some, if not actual, then at least possible, phenomena from being physical. For if we cannot even conceive of something being nonphysical, it is difficult to grasp what physicalists could be arguing for — to say nothing of what that they could be arguing against.3 It is not at all clear, however, that physicalists can provide even this minimal condition. Current physics, which posits such things as particles with no determinate location, curved space–time, and wave–particle duality, tells us that the world is indeed more ghostly than any ghost in the machine. And if the existence [1] The term ‘fundamental’ can, if you like, stand for whatever dependence relation you prefer. That is,

when I say that the mind–body problem is the question of whether mentality is fundamentally nonmental you can substitute the question of whether mentality is reducible to (or constituted by, or supervenient on, etc.) the nonmental. Of course, the various notions of dependence are not unproblematic themselves, and there is little agreement on what relations between the lower level physical phenomena and higher lever mental phenomena suffice for physicalism. But let us take one problem at a time: the problem I am concerned with here is here is not how to understand the dependence relation, but how to understand the dependence base. [2] While I use the term ‘mentality’ rather than the more specific term ‘experience’, most of what I say is directed at those engaged in the debate about experience, since many of those writing about intentionality already focus on the intentional/nonintentional distinction rather than the physical/nonphysical distinction. Fodor (1987) is a good example: ‘if the semantic and intentional are real properties of things, it must be in virtue of their identity with (or maybe supervenience on?) properties that are themselves neither intentional nor semantic.’ (Thanks to Joseph Levine for pointing this out to me.) [3] At the 1999 Robert S. Cohen Colloquium: Naturalism and its Discontents, Kim emphasized this as does Stroud (1996).

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of ghostly phenomena does not falsify physicalism it is difficult to say what would. As Richard Healey puts it, ‘[the] expanding catalogue of elementary particle states of an increasingly recondite nature seems to have made it increasingly hard for the physicists to run across evidence that would cast doubt on a thesis of contemporary physicalism stated in terms of it’ (Healey, 1979, p. 208). In other words, if such things as one-dimensional strings and massless particles are physical, it is difficult to say what wouldn’t be. Bertrand Russell made this basic point back in 1927: ‘matter,’ he said, ‘has become as ghostly as anything in a spiritualist’s séance.’4 And over the past seventy years Russell’s point has, if anything, been reinforced. Presumably things could change. Philosophy, as we all know, is not noted for its rapid progress and perhaps in another seventy years or so we will have a clear idea of what it means to be physical. However, it seems to me that until such clarification comes about, we ought to rethink the project of accommodating the mental in the physical world. That is, we ought to rethink what Kim tells us is ‘the shared project of the majority of those who have been working on the mind–body problem over the past few decades’ (Kim, 1998, p. 2). Not surprisingly, most physicalists are of a somewhat different opinion. While many physicalists admit that our understanding of what it means to be physical is rather tenuous, they usually think that the notion, and thus the crux of the debate, is clear enough. The mind–body problem, according to most physicalists, is the problem of explaining how the mind can be physical, where what counts as physical is given to us by science. In John Searle’s words, the mind–body problem is the problem of locating mentality ‘within our overall “scientific” conception of the world’.5 And so, it does not matter what kinds of ghostly and bizarre phenomena science may posit, for it is science itself that serves as a reality test. Searle thinks mentality passes the test because mentality, he argues, is ‘as much part of our biological natural history as digestion’ (Searle, 1992). Others, however, are a bit harsher in their grading policy. According to Patricia Churchland, for example, it is premature to say that every aspect of what we now think of as mentality can be accommodated in our scientific world-view (and for Churchland the relevant science here is neuroscience) since, for all we know, certain aspects of mentality might fail the test and go the way of phlogiston (Churchland, 1995). Yet as different as their views may be, both Searle and Churchland, as well as most other physicalists, abide by Wilfred Sellars’ well known dictum, ‘in the dimension of describing and explaining the world, science is the measure of all things, of what is that it is, and of what is not that it is not.’6 Physicalists may disagree about just how far to take this claim: must we be ‘nothing butists’, or can we accept an ontology that goes beyond science as long as it is related to the posits of science ‘in the

[4] Russell (1927/1992) p. 78. In an interesting forthcoming paper Galen Strawson points out that Joseph

Priestley made more or less the same point in 1777. [5] Searle (1992) p. 84. To be sure, Searle is also not satisfied with the current terminology used to

describe the mind–body problem. [6] Sellars (1963) p. 173. Or as Quine (1981) puts it, ‘it is within science itself, and not in some prior

philosophy, that reality is to be identified and described’ (p. 21).

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proper way’?7 However, when it comes to fundamental ontological matters, they are, for the most part, united: the ultimate authority is science. But what is meant here by ‘science’? Physicalists usually shy away from expressing their views about which specific theories will account for the fundamental nature of, as it were, everything. And this, of course, is the safest strategy. For as David Lewis advises, physicalists should ‘side with physics, but not take sides within physics’ (Lewis, 1983, p. 364). Samuel Guttenplan advocates this strategy as well; in his words, ‘all we [physicalists] are claiming is that any phenomenon that is a genuine happening in this world is in principle explicable by a science albeit by a science that might be quite different from any we now have at our disposal’ (Guttenplan, 1995, p. 77). But if this is all that physicalists are claiming, it is difficult to see what prevents anything from being physical: if physics (correctly) tells us that some things have no mass or no determinate spatial location, well then, physicalists will say, those things will still count as physical. Even if physics were to one day reveal that our current theory of space–time is mistaken and that space and time actually are distinct so that some phenomena have temporal, but not spatial properties, then physicalists, I assume, would say that those things too, if they actually exist, will be physical. Even more, if, as some physicists have begun to speculate, there is some sort of nonspatial, nontemporal stuff out of which space–time itself emerges, physicalists will once again declare victory.8 But if this is so, it seems that the strategy of simply siding with science, whatever science may ultimately say, is so safe as to bestow physicalism with what Popper thought was the very unscientific virtue of being, even in principle, unfalsifiable. Perhaps the deep eternal truths that are the domain of philosophy as well as mathematics are not at all likely to be falsifiable. Yet it seems that without any restrictions on how the science in question is to progress, or on what entities and properties it is to incorporate, physicalism, that is, the view that everything is physical, becomes not only unfalsifiable, but also trivial.9 That is, without any restrictions whatsoever, the view that everything is physical ends up as the view that everything exists. And this, it seems to me, is a position that most philosophers, save, of course, for Meinongians, are not interested in discussing. [7] Credit goes to William Wimsatt for the droll phrase ‘nothing butists’. [8] See Greene (1999). Speculation about such nonspatial, nontemporal stuff (or perhaps it would be

better to call it ‘nonstuff’) should also be a bit worrisome for those who define the abstract over the nonspatiotemporal — do we want to say that our spatial world emerges out of abstracta? [9] Even if the results of mathematics, if true, are necessarily true, an argument is only interesting if there is some step in it that is not immediately obvious to everyone. (Why bother publishing a proof that everyone already knows?) Perhaps certain sceptical hypotheses, such as the hypothesis that the world was created five minutes ago with all apparent evidence of an earlier creation in place, are also, even in principle, unfalsifiable. But while we could never have evidence that could show such a hypothesis to be mistaken, there would still be an objective difference between the two situations — God, as it were, could know that the hypothesis is false. But if being physical amounts to simply existing, it is not clear that physicalism would be falsifiable even for God. Interestingly enough, Quine (1981) seems to accept the triviality of physicalism. For as he says, ‘if the physicist suspected there was any event that did not consist in a redistribution of the elementary states allowed for by his physical theory he would seek a way of supplementing his theory’ (p. 98).

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While a number of physicalists, including Lewis himself, have tried to avoid this obstacle in their formulations of physicalism, I think that ultimately there is no way around it.10 As long as one defines the physical in relation to what science tells us about the world, the problem of explaining what it means to be physical in the context of the mind–body problem, a problem I call ‘the body problem’, currently has no solution.11 But what is left of the mind–body problem if we have no notion of body? In other words, is there room for the mind–body problem in a post-physical world?12

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II: Is There Still a Mind–Body Problem? One might think that the only reasonable conclusion to draw from the view that we have no notion of the physical is that we should give up the mind–body problem altogether: declare it dissolved and move on to other, hopefully betterdefined, problems. And as far as I know, most of those who argue that we have no philosophically useful notion of the physical are, it seems inevitably, drawn to this conclusion. Noam Chomsky is a good example. He tells us, ‘we can speak intelligibly of physical phenomena (processes, etc.) as we speak of the real truth or the real world, but without supposing that there is some other truth or world’ (Chomsky, 1998, p. 438). And he takes this to mean, ‘we have no coherent way to formulate issues related to the “mind–body problem”’ (Chomsky, 1995, p. 5; see also Chomsky, 1993). Similarly, Bas van Fraassen argues that the fact that physicalists will usually count ‘whatever science comes up with’ as physical shows that the thesis of physicalism lacks content (van Fraassen, 1996, p. 167). Chris Daly, who, in a recent paper, argues quite forcefully that we have no notion of a physical property, concludes, ‘no debate between physicalism and dualism can even be set up’ (Daly, 1998, p. 213; also see Scheffler, 1950). While Tim Crane and Hugh Mellor, after finding flaws with a wide variety of proposals for defining physicalism, conclude that their paper ‘should really be the last paper on the subject’ (Crane and Mellor, 1990, p. 83). The pattern is clear. And it is not at all difficult to see the motivation behind it: for if we have no notion of the [10] See Lewis (1983). Lewis tries to carve out a position that is not trivial by explaining the physical in

terms of whatever a future physics, which is significantly similar to current physics, but much improved, will tell us about the world. While one would like some explanation of what counts as ‘significantly similar’ and ‘much improved’, the main difficulty with this notion of the physical is that if some groundbreaking discovery is made and physics goes through a major revolution, resulting in it not being sufficiently similar to today’s physics, physicalists would, most likely, not want to claim the new posits and laws of this physics as being nonphysical. For other attempts to solve the body problem see Hellman (1985), Papineau (1993), Poland (1994), Meehl and Sellars (1956), Melnyk (1997), Smart (1978), Snowdon (1989). [11] In Montero (1999) I present an in-depth argument for this point. Since the main focus of this paper is to present a new way of thinking about the mind–body problem in light of the view that we have no solution to the body problem, my discussion here of this point will be brief. However, in arguing here for my proposed focus on the mind–body problem, I will also be arguing against retaining our current focus on the question of whether mentality is physical. [12] I should mention that I am not the first to use the term, ‘post-physicalism’. John Post suggests that ‘a far happier name [for his non-reductive physicalism], surely, would be “post-physicalism”.’ See Post (1987) p. 18.

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physical, there seems to be little use in asking how the mind could be physical and, thus, little point in discussing the mind–body problem. But is this the only conclusion one can draw? Must our inability to solve the body problem lead to the demise of the mind–body problem as well? To be sure, one obvious worry about concluding that we must abandon the mind–body problem is that, as a matter of fact, very few will follow suit. Philosophy, it has been said, has a penchant for burying its undertakers, and despite repeated pronouncements of the death of the mind–body problem, most people feel that a problem of some sort — perhaps of a very deep sort — remains. Even Crane and Mellor realize that this creates some tension in their view. For after stating quite boldly that their paper should definitely be the last on the topic, they also sheepishly admit that they actually know it will not. And here they were certainly right. Since their paper came out, about ten years ago, the question, ‘what is the fundamental nature of the mind?’ — a question to which ‘it is physical’ is supposed to provide an answer — has, if anything, been even more widely discussed. But why is this, if, as the title of their paper proclaims, ‘there is no question of physicalism’? Of course, the mere fact that many continue thinking about a problem does not show that a problem really exists. For it might be that no one has listened to Crane and Mellor’s protests that we have no notion of the physical capable of grounding questions about whether the mind is physical. While there may be something to this, there is more to be said. For there actually is an interesting question to ask about the fundamental nature of the mind. It is just not the question of whether the fundamental nature of the mind is physical. What other broad, philosophical questions can we ask about the fundamental nature of the mind — questions, that is, which could reasonably be thought to address the set of concerns that we have come to think of as the mind–body problem? Certainly, even if there were no philosophical problem called ‘the mind– body problem’, there would still be specific questions about the mind left to investigate. For example, regardless of whether we have a notion of the physical, we may still arrive at a deeper understanding of our mental lives, perha...